There are around 750 members in the House of Lords at the moment. There are 4 types of Lords like:
Life Peers
Law Lords
Bishops
Elected hereditary Peers
Unlike the MPs, the Lords are not elected by the people of UK. Most of the Lords are appointed by the Queen on the recommendation of the Prime Minister and the rest are appointed by the House of lords Appointments’ Commission.
Life Peers
These Lords are appointed for their lifetime. However their membership is not carried over to their children. On the advice and recommendation of the Prima Minister, the Queen formally appoints Life Peers.
Law Lords (Lords of Appeal)
The Law Lords are the salaried full tome judges of the house of lords. They carry out all the legal functions of the House of Lords, which is the apex court of the country. The law lords are appointed by the Queen on the recommendation of the Prime Minister, who is again advised by the Lord Chancellor. The candidates for the posts of law lords usually come from the judges of the Court of Appeal in England and Wales, The Court of Sessions in Scotland and the Court of Appeal in Northern Ireland
Archbishops and Bishops
26 archbishops and bishops from 26 Churches of England sit in the House of Lords. They pass their membership to the next seniormost Bishop when they retire. However, the Archbishops of Canterbury and York traditionally get Life Peerages on retirement.
Elected hereditary Peers
In 1999, the House of Lords, by the House of lords Act had eradicated the right of hereditary Peers to sit and vote in the House of Lords. However 92 members were internally elected to remain until the next set of the Lords reform process.